1. Field of the Invention
The present invention relates to a method of reproducing a digital broadcast, and more particularly, to a method and apparatus for reproducing a digital broadcast which supports at least two compression formats and a method of recording the digital broadcast.
2. Description of the Related Art
In conventional general analog television broadcasts, image signals are amplitude modulated or frequency modulated and then are transmitted by using electric waves and wired cables. However, currently, standardization and regularization of digital television broadcasts are rapidly progressing due to development of digital technologies such as digital image compression and digital modulation/demodulation. Furthermore, conventional territorial, satellite, and cable broadcasts are also tending to be digitized based on Moving Picture Experts Group (MPEG) formats.
Digital broadcasting may provide a higher quality broadcasting service than an analog broadcasting signal service, in accordance with the development of a digital image/sound compression technology and a digital transmission technology. In particular, in digital broadcasting, a plurality of broadcast programs may be multiplexed and transmitted in the same band and mutual operations of digital communication media and digital storage media may be greatly improved.
Also, in digital broadcasting, a plurality of broadcast programs encoded based on the MPEG formats are multiplexed and then transmitted in the form of transport streams. The transport streams are received by a digital broadcasting receiver such as a set-top box and the broadcast programs included in the transport streams are demultiplexed.
Accordingly, only one program, which a user wants, is selected. The selected program is restored into original audio and video signals by using a decoder included in the digital broadcasting receiver such as the set-top box, and is transmitted and output to an audio/video output device such as a television.
Furthermore, currently, a digital broadcasting receiver such as a personal video recorder (PVR) has a digital broadcast recording/reproducing function. The digital broadcasting receiver such as a PVR includes a high-capacity hard disk so that the broadcast programs transmitted and output to the audio/video output device such as the television may be stored in the hard disk and then output and reproduced upon a user's request.
The PVR, which supports conventional Moving Picture Experts Group 2 (MPEG2) formats, performs random access by using a sequence (SEQ) header and a location of an I picture of an MPEG2 transport stream and performs trick-play functions such as pausing, instant playing, rewinding, etc. by using locations of an I picture, a predictive (P) picture, and a bidirectional (B) picture of the MPEG2 transport stream.
Digital broadcasts in both the H.264 format and the MPEG2 format are in use, thus transport streams in both the MPEG2 format and the H.264 format are broadcast. Since the MPEG2 and H.264 formats are different compression formats, an H.264 transport stream has a different structure from an MPEG2 transport stream. Thus, the conventional PVR may not consistently perform trick-play functions when the H.264 transport stream is received.